Ignition control device for internal combustion engine

Abstract

A temperature compensated ignition control device for advancing ignition timing during low temperature operation of the engine wherein the temperature sensor may be mounted at any number of locations as long as the temperature it senses at the start of the engine is the same as the actual temperature at the time of engine starting. The ignition advance is determined based on the temperature sensed at the start of the engine and a preprogrammed relationship between the sensed temperature where the sensor is located and the actual engine temperature at predetermined time periods after the start of the engine and igniton timing control characteristics.

We claim: 
     
       1. An electronic ignition control device for an internal combustion engine comprising a spark advance control circuit for controlling the ignition timing of the engine during low temperature operation after the start of the engine, a temperature sensor for sensing temperature at the start of the engine and transmitting a signal to said control circuit indicative of the sensed temperature at the start of the engine, said control circuit including a central processing unit and a memory wherein the central processing unit computes optimum ignition timing after the start of the engine during low temperature operation of the engine based on the temperature sensed only at the start of the engine and a preprogrammed relationship stored in the memory between the sensed temperature where the temperature sensor is located and the actual temperature of the engine at predetermined time periods after the start of the engine and ignition timing control characteristics. 
     
     
       2. An electronic ignition control device as recited in claim 1, wherein said temperature sensor is located so that the temperature it senses at the start of the engine is substantially the same as the temperature of the engine at the start of the engine. 
     
     
       3. A method for controlling ignition timing in an internal combustion engine during low temperature operation after the start of the engine, comprising the steps of sensing temperature with a temperature sensor at the start of the engine, transmitting a signal to a spark advance control circuit indicative of the sensed temperature at the start of the engine, determining optimum ignition timing after the start of the engine during low temperature operation of the engine based on the sensed temperature at the start of the engine and a preprogrammed relationship stored in a memory of the spark advance control circuit between the sensed temperature where the sensor is located and the actual engine temperature at predetermined time periods after the start of the engine and ignition timing control characteristics. 
     
     
       4. A method for controlling ignition timing as recited in claim 3, wherein the temperature sensor is located so that the temperature it senses at the start of the engine is substantially the same as the temperature of the engine at the start of the engine.